Respiratory pressures in boys from 11-17 years old: a semilongitudinal study.

We hypothesized that in children, maximal respiratory pressures increase with age and more during the pubertal growth spurt. The aim of this work was to follow maximal respiratory pressures, with a semilongitudinal study, in three groups of prepubertal, peripubertal, and postpubertal children in order to specify pressure changes with age and determine the contributions of growth and puberty. A semilongitudinal study was conducted in 44 boys assigned to three overlapping age groups: from 11-13 (prepubertal stage), from 13-15 (pubertal stage), and from 15-17 years (postpubertal stage). The children underwent annual testing for maximal respiratory pressures and spirometric values. Body mass, height, lean body mass assessed from four skinfold thicknesses, and stage of development were also evaluated. Maximal respiratory pressure increased significantly with growth from 11-17 years for maximal inspiratory pressure, and from 11-15 years for maximal expiratory pressure. We observed an increase in the slope of the regression lines between age and lean body mass during the pubertal growth spurt, without an increase in the slopes of the regression lines between age and respiratory pressures. In conclusion, the relationships between age and respiratory pressures are not modified by the growth spurt, indicating that anthropometric characteristics have little role in determining respiratory pressures.